Construction of supported organometallics using cycloplatinated arylamine ligands

Article abstract of DOI:10.1021/om010500g

The preparation of ortho-chelating aminoaryl ligands ([C₆H₃(CH₂NMe₂)-2-R-4]^-, abbreviated as C,N) containing a pendant hydroxymethyl group is described. These ligands have been cycloplatinated with cis-PtCl₂(DMSO)₂, yielding the corresponding C,N-platinum(II) complexes. The pendant hydroxymethyl substituent is a versatile group for attachment of the organometallic moiety to macromolecules, which has been demonstrated by attaching the C,N-platinum complexes to a dendritic wedge and to C₆₀.

Full text of DOI:10.1021/om010500g

264
Organometallics 2002, 21, 264-271
Con str u ction of Su p p or ted Or ga n om eta llics Usin g
Cyclop la tin a ted Ar yla m in e Liga n d s
Michel D. Meijer,† Arjan W. Kleij,† B. Scott Williams,† Dianne Ellis,‡
Martin Lutz,‡ Anthony L. Spek,‡,§ Gerard P. M. van Klink,† and
Gerard van Koten*,†
Department of Metal-Mediated Synthesis, Debye Institute, Utrecht University, Padualaan 8,
3584 CH Utrecht, The Netherlands, and Department of Crystal and Structural Chemistry,
Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8,
3584 CH Utrecht, The Netherlands
Received J une 11, 2001
The preparation of ortho-chelating aminoaryl ligands ([C6H3(CH2NMe2)-2-R-4]-, abbrevi-
ated as C,N) containing a pendant hydroxymethyl group is described. These ligands have
been cycloplatinated with cis-PtCl2(DMSO)2, yielding the corresponding C,N-platinum(II)
complexes. The pendant hydroxymethyl substituent is a versatile group for attachment of
the organometallic moiety to macromolecules, which has been demonstrated by attaching
the C,N-platinum complexes to a dendritic wedge and to C60.
In tr od u ction
-platinum(II) complexes (NCN ) [C6H2(CH2NMe2)2-2,6-
R-4]-), yielding macromolecular catalysts and SO2-sens-
ing dendritic macromolecules, respectively.5,10 To de-
velop this approach for the C,N-ligand, we have studied
the synthesis and structural characterization of a series
of cycloplatinated C,N-derived ligands containing a
pendant hydroxymethyl group (para to the CH2NMe2
substituent). This group serves as a suitable linker for
attachment of the organometallic fragment to the mac-
romolecular framework. In this fashion, C,N-platinum-
(II) complexes have been anchored to a Fre´chet-G1
dendron and to C60.
One of the most rapidly developing fields in organo-
metallic chemistry is the construction of supramolecular
structures1 and organometallic assemblies.2 In some
cases, the macromolecular structures contain (metal)
sites or functional groups that can lead to new materi-
als, applicable in host-guest chemistry3 and catalysis4
or as sensors.5 In the construction of these materials,
organometallic moieties have been introduced via a
ligand modification/immobilization and subsequent met-
alation step, which is not always the optimal procedure.
For example, we have encountered unexpected inter-
and intramolecular complexation behavior of C,N-de-
rivatized carbosilane dendrimers (C,N ) C,N-chelating
[C6H3(CH2NMe2)-2-R-4]-) during metalation steps, re-
sulting in the formation of multimetallic aggregates.6
An approach to circumvent these interactions involves
the attachment of a complete organometallic moiety to
a macromolecular structure or to a support. This has
been successfully demonstrated with supports such as
silica surfaces,7 (hyperbranched) polymers,8 dendrim-
ers,9 and more recently, for the functionalization of the
periphery of dendrimers with NCN-palladium(II) and
Resu lts a n d Discu ssion
Syn th esis a n d Ch a r a cter iza tion of Cyclop la ti-
n a ted C,N-Com p lexes. Synthetic protocols were de-
veloped for cycloplatinated C,N-complexes containing a
hydroxymethyl group, which can be used as a linker to
attach the organoplatinum fragment to a macromolecu-
lar structure. 4-[(Dimethylamino)methyl)]benzaldehyde
was reacted with LiAlH4, affording benzyl alcohol 1
(Scheme 1). Direct cycloplatination of 1 with an equimo-
lar amount of cis-PtCl2(DMSO)2 in the presence of
NaOAc yielded the platinum DMSO derivative 2, which
was converted into the corresponding triphenylphos-
phine derivative 3 via ligand exchange.
* To whom correspondence should be addressed. E-mail: g.vankoten@
chem.uu.nl. Fax: +(31) 30 2523615.
To double the number of organometallic units per
hydroxyl linking group, the bis(H-C,N)-ligand 4 has also
been prepared (Scheme 2). Treatment of 4-[(dimethyl-
amino)methyl)]benzaldehyde with an equimolar amount
† Debye Institute.
‡ Bijvoet Center for Biomolecular Research.
§ Address correspondence pertaining to crystallographic studies to
this author. E-mail: a.l.spek@chem.uu.nl.
(1) Lehn, J .-M. Angew. Chem., Int. Ed. Engl. 1990, 29, 1304.
(2) (a) Stang, P. J .; Olenyuk, B. Acc. Chem. Res. 1997, 30, 502. (b)
Leininger, S.; Olenyuk, B.; Stang, P. J . Chem. Rev. 2000, 100, 853.
(3) Vo¨gtle, F. Comprehensive Supramolecular Chemistry; Pergamon/
Elsevier Press: New York, 1997; Vol. 2.
(4) (a) Sanders, J . K. M. Chem. Eur. J . 1998, 4, 1378. (b) Kirby, A.
J . Angew. Chem., Int. Ed. Engl. 1996, 35, 707.
(7) (a) Price, P. M.; Clark, J . H.; Macquarrie, D. J . J . Chem. Soc.,
Dalton Trans. 2000, 101. (b) Macquarrie, D. J .; Fairfield, S. E. J . Mater.
Chem. 1997, 7, 2201. (c) van de Kuil, L. A.; Grove, D. M.; Zwikker, J .
W.; J enneskens, L. W.; Drenth, W.; van Koten, G. Chem. Mater. 1996,
6, 1675.
(5) (a) Albrecht, M.; Gossage, R. A.; Spek, A. L.; van Koten, G. Chem
Commun. 1998, 1003. (b) Albrecht, M.; van Koten G. Adv. Mater. 1999,
11, 171. (c) Albrecht, M.; Lutz, M.; Spek, A. L.; van Koten, G. Nature
2000, 406, 970.
(6) (a) Kleij, A. W.; Kleijn, H.; J astrzebski, J . T. B. H.; Smeets, W.
J . J .; Spek, A. L.; van Koten, G. Organometallics 1999, 18, 268. (b)
Kleij, A. W.; Klein Gebbink, R. J . M.; van den Nieuwenhuijzen, P. A.
J .; Kooiman, H.; Lutz, M.; Spek, A. L.; van Koten, G. Organometallics
2001, 20, 634.
(8) Schlenk, C.; Kleij, A. W.; Frey, H.; van Koten, G. Angew. Chem.,
Int. Ed. 2000, 39, 3445.
(9) For reviews on this subject, see: (a) van Koten, G.; J astrzebski,
J . T. B. H. J . Mol. Catal. A 1999, 146, 317. (b) Majoral, J . P.; Caminade,
A.-M. Chem. Rev. 1999, 99, 845. (c) Newkome, G. R.; He, E.; Moorefield,
C. N. Chem. Rev. 1999, 99, 1698. (d) Bosman, A. W.; J anssen, H. M.;
Meijer, E. W. Chem. Rev. 1999, 99, 1665.
(10) Dijkstra, H. P.; Albrecht, M.; Ronde, N.; van Klink, G. P. M.;
Vogt, D.; van Koten, G., to be published.
10.1021/om010500g CCC: $22.00 © 2002 American Chemical Society
Publication on Web 12/19/2001

Cycloplatinated Arylamine Ligands
Sch em e 1. Syn th esis of 3a
Organometallics, Vol. 21, No. 2, 2002 265
Ta ble 1. Selected 1H NMR Da ta a ,b for 1-6
complex
Hortho
aryl-H
CH2N
NMe2
OH
1
2
3
4
5
6
7.31, 7.26
7.11, 7.06
7.04, 7.82
7.29, 7.20
7.13, 6.99
6.70, 5.90
3.40
2.20
3.06
1.70
0.68
5.08
2.29
0.52
7.92
6.34
3.98
2.90
3.96
2.97
2.13
2.98/2.88
2.97/2.95
3.34
8.03
6.43
3.94/3.91c
4.02/3.98c
a
300 MHz, CDCl3, δ in ppm. bPlatinum and phosphorus
c
couplings not included. AB system.
a
Reagents and Conditions: (i) LiAlH4, Et2O, 0 °C; (ii) cis-
PtCl2(DMSO)2, NaOAc, MeOH, 65 °C; (iii) PPh3, CH2Cl2.
Sch em e 2. Syn th esis of 6a
F igu r e 1. Part of the 1H NMR spectrum of 6, showing
the resonances for the benzylic and NMe2 protons.11
attributed to intramolecular interaction with the DMSO
and PPh3 ligands. Similar behavior was observed for the
aryl protons of the platinum complexes, which also
shifted to higher field with respect to the signals in the
parent ligands.
For the bis-C,N complexes 5 and 6, two resonances
with platinum (and phosphorus for 6) couplings were
observed for the NMe2 groups. The resonances for the
protons on the benzylic positions (donor arms) were
observed as AB patterns (Figure 1), which reflects the
stereogenicity of the para substituent.11 This pattern
was observed not only for 5 and 6 but also for all
complexes derived from 6 (see below). 195Pt-31P cou-
plings of 4261 Hz (3) and 4281 Hz (6), respectively, were
observed by 31P{1H} NMR spectroscopy. These data are
consistent with the depicted structures of 3 and 6, i.e.,
with the PPh3 ligand trans to the nitrogen donor atom.
Compound 6 was further characterized by a single-
crystal structure determination. The molecular struc-
ture of 6 in the solid state (Figure 2) comprises two
platinum(II) metal centers, which each have a distorted
square planar environment (Table 2), with C,N-bite
angles of 80.8(2)° and 81.2(2)°. The substituents O(1)
and H(10) at carbon atom C(10) are positionally disor-
dered (pseudo-2-fold rotation axis). Only the major
disorder component (54.7% occupancy) is shown in
Figure 2. No hydrogen-bonding interaction was observed
for 6 in the solid state between the C(H)OH and Pt-Cl
groupings such as has been observed for the corre-
sponding complexes [PtCl(C6H2{CH2NMe2}2-2,6-OH-4)]5
and [PtCl(C6H2{CH2NMe2}2-2,6-{CH2OH}-4)].12
aReagents and Conditions: (i) 2 equiv of t-BuLi, Et2O, -78
°C to rt; (ii) 2 equiv of cis-PtCl2(DMSO)2, 2 equiv of NaOAc,
MeOH, 65 °C; (iii) 2 PPh3, CH2Cl2.
of the lithium reagent [Li{C6H4(CH2NMe2)-4}] in diethyl
ether yielded the bis(H-C,N)-functionalized derivative
4. The introduction of a platinum center in each of the
two C,N-sites was achieved using the same methodology
as described for 2, producing the bisplatinum compound
5 as a white solid. Subsequent treatment of 5 with PPh3
in CH2Cl2 afforded bisphosphine complex 6.
The platinum complexes 3 and 6 were characterized
by NMR spectroscopy (1H (Table 1), 13C{1H}, and 31P)
and elemental analysis. Remarkably high field shifts of
the pendant OH groups were observed by 1H NMR
spectroscopy (CDCl3, Table 1). These shifts can be
Der iva tiza tion of 3 a n d 6. The organometallic
fragments 3 and 6 were prepared for use as precursors
in the synthesis of larger macromolecular structures.

266 Organometallics, Vol. 21, No. 2, 2002
Meijer et al.
Sch em e 3a
F igu r e 2. Displacement ellipsoid plot (50% probability
level) of the molecular structure of 6, with the adopted
numbering scheme. All hydrogen atoms except H(1) and
H(10) have been omitted for clarity. The substituents O(1)
and H(10) at carbon atom C(10) are positionally disordered
(pseudo-2-fold rotation axis). Only the major disorder
component (54.7% occupancy) is shown.
Ta ble 2. Selected Bon d Dista n ces (Å) a n d An gles
(d eg) of 6
a
Reagents and Conditions: (i) [G1]-C(O)Cl, NEt3, CH2Cl2.
Pt(1)-Cl(1)
Pt(1)-P(1)
Pt(1)-N(1)
Pt(1)-C(1)
Cl(1)-Pt(1)-P(1) 93.08(4)
Cl(1)-Pt(1)-N(1) 91.59(11)
P(1)-Pt(1)-C(1) 94.39(13)
N(1)-Pt(1)-C(1) 80.85(17)
P(1)-Pt(1)-N(1) 175.04(11)
Cl(1)-Pt(1)-C(1) 171.87(13)
2.3917(12)
2.2270(11)
2.143(4)
Pt(2)-Cl(2)
2.3856(11)
2.2282(12)
2.164(4)
2.016(4)
92.35(4)
91.56(11)
94.98(13)
81.24(17)
175.50(11)
172.11(13)
Sch em e 4a
Pt(2)-P(2)
Pt(2)-N(2)
Pt(2)-C(2)
2.025(4)
Cl(2)-Pt(2)-P(2)
Cl(2)-Pt(2)-N(2)
P(2)-Pt(2)-C(11)
N(2)-Pt(2)-C(11)
P(2)-Pt(2)-N(2)
Cl(2)-Pt(2)-C(11)
interplanar angle Pt(1)-Cl(1)-P(1) and Pt(1)-N(1)-C(1) 3.42(18)
Pt(2)-Cl(2)-P(2) and Pt(1)-N(1)-C(1) 3.98(17)
The pendant hydroxymethyl group in the platinum
complexes 3 and 6 is well suited for direct reaction with
acid chloride-substituted dendrimers or dendrons. More-
over, reaction with malonyl chloride enables coupling
to C60 using the Bingel cyclopropanation reaction.13 To
demonstrate the use of C,N-platinum complexes in the
synthesis of macromolecular structures based on den-
drimers, the C,N-platinum complex 3 was attached to
a small Fre´chet type dendron/wedge.14 Addition of [G1]-
C(O)Cl to an equimolar amount of 3 in CH2Cl2 in the
presence of base (NEt3) yielded the dendritic platinum-
(II) complex 7 in 65% isolated yield (Scheme 3). Con-
clusive evidence for the formation of 7 was provided by
the disappearance of the doublet resonance assigned to
the benzylic protons of the hydroxymethyl group in 3
(δ ) 3.96) and the appearance of a new singlet reso-
nance at 4.62 ppm, attributed to the methylene group
of the newly formed ester linkage. Furthermore, MALDI-
TOF mass spectrometric analysis displayed the molec-
ular ion peak [M]+ and a [M - Cl]+ peak for m/z 972.82
and 938.07, respectively. Similar 195Pt-31P coupling
constants were observed for 3 (J ) 4261 Hz) and for
the [G1] dendrimer complex 7 (J ) 4235 Hz). This
a
Reagents and Conditions: (i) ethyl malonyl chloride,
pyridine, or NEt3, Et2O, 0 °C; (ii) NaI, acetone.
suggests an unchanged spatial arrangement of the
ligands about the platinum center. Moreover, the high-
yield synthesis of 7 and its purity demonstrate the
stability of the cycloplatinated C,N-building block.
Syn t h esis of F u ller en e Der iva t ives. Methano-
fullerene C,N-platinum complexes are accessible via two
routes: (a) preparation of the methanofullerene ligand
followed by transmetalation, or (b) direct cyclopropa-
nation of C60 with a malonate C,N-platinum complex.
Both routes were studied for comparison. For this
purpose, ethyl malonyl tails were attached not only to
the C,N-platinum complexes 3 and 6 but also to the
parent C,N-ligands 1 and 4. Reaction of 1, 3, 4, and 6
with ethyl malonyl chloride in Et2O in the presence of
base (NEt3 or pyridine) at 0 °C afforded the correspond-
ing malonate compounds 8-11 (Scheme 4). To avoid
halogen scrambling (i.e, chloride-iodide exchange by I2
during the Bingel reaction of the platinum-chloride
(11) Compounds 4-6 (and their derivatives) are interesting cases
of an achiral XYCR2 system where the C-center is prochiral, but any
prochiral center in R is diastereotopic. For 4, only singlets were
observed by 1H NMR, most likely due to a too small ∆δ for the benzylic
protons and NMe2 groups.
(12) Slagt, M. Q.; van de Coevering, R.; Klein Gebbink, R. J . M.;
Lutz, M.; Spek, A. L., van Koten, G., unpublished results.
(13) See for instance: (a) Bingel, C. Chem. Ber. 1993, 126, 1957. (b)
Nierengarten, J .-F.; Felder, D.; Nicoud, J .-F. Tetrahedron Lett. 1998,
2747, and references therein.
(14) (a) Hawker, C. J .; Fre´chet, J . M. J . J . Am. Chem. Soc. 1990,
112, 7638. (b) Wooley, K. L.; Hawker, C. J .; Fre´chet, J . M. J . J . Am.
Chem. Soc. 1990, 112, 4253. (c) Albrecht, M.; Hovestad, N. J .; Boersma,
J .; van Koten, G. Chem. Eur. J . 2001, 7, 1289.

Cycloplatinated Arylamine Ligands
Organometallics, Vol. 21, No. 2, 2002 267
Ta ble 3. Selected Bon d Dista n ces (Å) a n d An gles
(d eg) of 10 a n d 13
10
13
Pt(1)-Cl(1)
Pt(1)-P(1)
Pt(1)-N(1)
Pt(1)-C(1)
Cl(1)-Pt(1)-P(1)
Cl(1)-Pt(1)-N(1)
P(1)-Pt(1)-C(1)
N(1)-Pt(1)-C(1)
P(1)-Pt(1)-N(1)
Cl(1)-Pt(1)-C(1)
interplanar angle
between
2.3902(7) Pt(1)-I(1)
2.2220(7) Pt(1)-P(1)
2.138(2) Pt(1)-N(1)
2.008(3) Pt(1)-C(1)
91.37(2) I(1)-Pt(1)-P(1)
90.02(6) I(1)-Pt(1)-N(1)
96.47(8) P(1)-Pt(1)-C(1)
81.95(10) N(1)-Pt(1)-C(1)
178.01(6) P(1)-Pt(1)-N(1)
168.50(7) I(1)-Pt(1)-C(1)
9.51(14) interplanar angle
between
2.6874(3)
2.2364(10)
2.172(3)
2.027(4)
92.83(3)
90.96(8)
95.29(11)
81.27(13)
175.79(9)
167.90(11)
8.38(10)
Pt(1)-Cl(1)-P(1) and
Pt(1)-N(1)-C(1)
Pt(1)-I(1)-P(1) and
Pt(1)-N(1)-C(1)
platinum centers in both 10 and 13 have a distorted
square planar coordination geometry, reflected by the
C,N-bite angles of 81.95(8)° for 10 and 81.26(14)° for
13, respectively. The ligand environment, i.e., the PPh3
ligands positioned trans to the NMe2 group and the
chloride ligand trans to the aromatic ring, was not
changed by the attachment of the malonyl group.
Der iva tiza tion of C60. The malonates 8 and 9 were
attached to C60 via a Bingel cyclopropanation reaction
in the presence of I2 and diazabicyclo[5.4.0]undec-7-ene
(DBU) in toluene at room temperature (Scheme 5). The
methanofullerenes 14 and 15 were characterized by
NMR and mass spectroscopic analysis (MALDI-TOF).
These methanofullerene CH,N ligands were reacted
with cis-PtCl2(DMSO)2 and NaOAc in a mixture of
MeOH and ortho-dichlorobenzene (ODCB, Scheme 5).
Cycloplatination at the C,N-ligand took place for 14,
affording the platinum(II)-DMSO complex 16, which
was isolated in 57% yield. To our surprise, no bisplati-
num complex starting from 15 was formed under the
same conditions. Only starting material and insoluble
products were isolated. However, direct attachment of
the platinum complexes 12 and 13 to C60 in the presence
of I2 and DBU did yield the new methanofullerene C,N-
platinum complexes 17 and 18, respectively. Both 17
and 18 were isolated in reasonable yields (60% and 59%
based on reacted C60), which again demonstrates the
stability of the C,N-platinum(II) building block. In the
1H NMR spectrum of 17 and 18, the methylene reso-
nance of the malonyl group of the starting material had
disappeared, indicating a complete reaction, while the
expected methanofullerene resonances in the 150-120
ppm region were observed by 13C{1H} NMR spectros-
copy. The 31P-195Pt coupling constants in the 31P{1H}
NMR spectrum of 4167 Hz (17) and 4174 Hz (18)
showed that the platinum center remained in the same
coordination environment during the Bingel reaction.
Mass spectrometric analysis (MALDI-TOF) exhibited
fragments at m/z 1454.0 (17) and 2170.1 (18), corre-
sponding to the respective [M - I]+ fragments ions.
These results show that the chelated platinum center
is stable under the conditions of the cyclopropanation
reaction. Apparently, the formation of the R-halocar-
banion and subsequent reaction with C60 is faster then
the alternative Pt-C(C,N) bond cleavage. Moreover, we
have found that the organometallic moiety of these
complexes is also stable to the chromatographic workup
conditions traditionally used in fullerene chemistry.
Grafting of a complete organometallic synthon to C60 is
thus a useful route for the synthesis of methanofullerene
C,N-platinum(II) complexes, especially in cases where
F igu r e 3. Displacement ellipsoid plot (50% probability
level) of the molecular structure of 10, with the adopted
numbering scheme. The hydrogen atoms have been omitted
for clarity.
F igu r e 4. Displacement ellipsoid plot (50% probability
level) of the molecular structure of 13, with the adopted
numbering scheme. All hydrogen atoms except H(10) have
been omitted for clarity. The structure of 13 has an exact,
crystallographic C2 symmetry, leading to rotational disor-
der at carbon C(10) and disorder of the ethyl malonyl chain
and the hydrogen atom H(10) (both in 50% occupancy, only
one disorder component is shown).
complexes 10 and 11), these complexes were converted
into their corresponding iodide complexes 12 and 13
with NaI in acetone. The formation of these compounds
was demonstrated by multinuclear NMR spectroscopy
and elemental analysis. For 10 and 13, the X-ray crystal
structure was also determined.
The molecular plots of the structures of 10 and 13 in
the solid state are shown in Figures 3 and 4, respec-
tively, while a selection of bond lengths and bond angles
is presented in Table 3. The structure of 13 has an exact,
crystallographic C2 symmetry axis, leading to rotational
disorder at carbon C(10) and disorder of the ethyl
malonyl chain and the hydrogen atom H(10) (both in
50% occupancy). Only one disorder component is shown
in Figure 4 (symmetry operation: 1 - x, y, 0.5 - z). The

268 Organometallics, Vol. 21, No. 2, 2002
Meijer et al.
a
received. The MALDI-TOF mass spectra were acquired using
a Voyager-DE BioSpectrometry Workstation mass spectrom-
eter (PerSeptive Biosystems Inc., Framingham, MA). Sample
solutions with an approximate concentration of 1 g L-1 in CH2-
Cl2 were prepared. The matrix was 9-nitroanthracene (9-NA)
with an approximate concentration of 40-50 g L-1. An 0.2 µL
aliquot of the sample solution and 0.2 µL of the matrix solution
were combined on a golden MALDI target and analyzed after
evaporation of the solvent. Elemental analyses were performed
by Dornis und Kolbe, Mikroanalytisches Laboratorium (Mu¨l-
heim, Germany).
Sch em e 5. Der iva tiza tion of C60
4-[(Dim eth yla m in o)m eth yl]ben zyl Alcoh ol (1). To a
suspension of LiAlH4 (3.27 g, 86.2 mmol) in Et2O (75 mL) at 0
°C was added a solution of 4-[(dimethylamino)methyl]benzal-
dehyde (7.03 g, 43.1 mmol) in Et2O (40 mL). The reaction
mixture was stirred for 20 h, carefully quenched with 10 mL
of a saturated aqueous solution of NaCl, and filtered. The
organic fraction was separated, dried over MgSO4, filtered, and
evaporated in vacuo to yield 1 as a colorless oil (4.97 g, 77%).
3
1H NMR (CDCl3): δ 7.31 (d, 2H, J ) 8.7 Hz, Ar-H), 7.26 (d,
2H, 3J ) 8.4 Hz, Ar-H), 4.65 (s, 2H, CH2OH), 3.40 (s, 2H,
CH2N), 3.06 (s, 1H, OH), 2.20 (s, 6H, NCH3). 13C{1H} NMR
(CDCl3): δ 140.1, 137.6, 129.3, 126.9 (aryl-C), 64.9 (COH), 64.0
(CH2N), 45.1 (NCH3). Anal. Calcd for C10H15NO: C 72.69, H
9.15, N 8.48. Found: C 72.56, H 9.21, N 8.44.
3-[Ch lor o(DMSO)p la tin o]-4-[(d im eth yla m in o)m eth yl]-
ben zyl Alcoh ol (2). To a solution of 1 (1.06 g, 6.42 mmol) in
MeOH (40 mL) was added cis-PtCl2(DMSO)2 (2.77 g, 6.55
mmol) and NaOAc (0.54 g, 6.6 mmol). The reaction mixture
was stirred at 65 °C for 3 h, whereupon a white solid separated
from the solution. The product was collected by decantation,
washed with MeOH (50 mL) and Et2O (2 × 50 mL), and dried
in vacuo, yielding 2 as a white solid (2.00 g, 66%). 1H NMR
(CDCl3): δ 7.92 (s, 3J (Pt-H) ) 47.4 Hz, 1H, Ar-Hortho), 7.11
2
2
(d, J ) 7.80 Hz, 1H, Ar-H), 7.06 (d, J ) 7.80 Hz, 1H, Ar-H),
2
3
4.64 (d, J ) 6.0 Hz, 2H, CH2O), 3.98 (s, J (Pt-H) ) 39.9 Hz,
2H, CH2N), 3.54 (s, J (Pt-H) ) 24.9 Hz, 6H, SCH3), 2.90 (s,
3
3J (Pt-H) ) 33.9 Hz, 6H, NCH3), 1.70 (t, 2J ) 6.0 Hz, 1H, OH).
13C{1H} NMR (CDCl3): δ 145.5, 138.7 (3J (Pt-C) ) 53.3 Hz),
136.2 (1J (Pt-C) ) 1061.3 Hz, Ar-Cipso), 132.9 (2J (Pt-C) ) 54.0
Hz), 123.9, 121.8 (3J (Pt-C) ) 36.4 Hz), 74.7 (2J (Pt-C) ) 51.5
Hz, CH2N), 65.8 (COH), 52.2 (NCH3), 46,8 (2J (Pt-C) ) 63.1
Hz, SCH3). Anal. Calcd for C12H20ClNO2PtS: C 30.48, H 4.26,
N 2.96. Found: C 30.34, H 4.21, N 2.85.
3-[Ch lor o(tr ip h en ylp h osp h in e)p la tin o]-4-[(d im eth yl-
a m in o)m eth yl]ben zyl Alcoh ol (3). To a suspension of 2
(1.01 g, 2.14 mmol) in CH2Cl2 (40 mL) was added PPh3 (0.59
g, 2.2 mmol). The reaction mixture was stirred for 2 h, filtered
through Celite, and evaporated in vacuo. The crude product
was washed with Et2O (2 × 50 mL) and dried in vacuo, yielding
3 as a white solid (0.90 g, 64%). 1H NMR (CDCl3): δ 7.79-
a
Reagents and Conditions: (i) C60, I2, DBU, toluene, rt, 24
h; (ii) cis-PtCl2(DMSO)2, NaOAc, MeOH/DCB (1:2 v/v %), 65 °C.
the methanofullerene ligand cannot be directly meta-
lated. In summary, the presented C,N-platinum com-
pounds have been shown to be versatile and stable
complexes, suitable in dendrimer and fullerene chem-
istry. These complexes are also promising building
blocks for other areas of macromolecular chemistry, e.g.,
for materials based on the use of metal d8 complexes.2
3
7.72 (m, 6H, PAr-H), 7.44-7.32 (m, 9H, PAr-H), 7.04 (d, J )
7.2 Hz, 1H, Ar-H), 6.82 (dd, 3J ) 7.7 Hz, 4J ) 1.8 Hz, 1H,
3
4
4
Ar-H), 6.34 (dd, J (Pt-H) ) 56.7 Hz, J (P-H) ) 2.6 Hz, J )
3
3
1.8 Hz, 1H, Ar-Hortho), 4.06 (d, J (Pt-H) ) 29.7 Hz, J (P-H)
) 3.0 Hz, 2H, CH2N), 3.96 (d, 3J ) 6.0 Hz, 2H, CH2O), 2.97 (d,
3J (Pt-H) ) 24.3 Hz, 3J (P-H) ) 3.3 Hz, 6H, NCH3), 0.68 (t, 3J
) 6.0 Hz, 1H, OH). 13C{1H} NMR (CDCl3): δ 146.91 (Ar-C),
Exp er im en ta l Section
1
2
138.04 (d, J (P-C) ) 6.7 Hz, PAr-Cipso), 137.57 (d, J (P-C) )
Gen er a l Com m en ts. All experiments were conducted
under a dry dinitrogen atmosphere using standard Schlenk
techniques. Solvents were dried over appropriate materials
2
3
2.4 Hz, Ar-C), 135.29 (d, J (P-C) ) 10.4 Hz, J (Pt-C) ) 39.5
Hz, PAr-Cortho), 130.77 (Ar-C), 130.55 (d, 4J (P-C) ) 2.4 Hz,
Ar-Cpara), 129.95 (3J (Pt-C) ) 36.3 Hz, Ar-C), 127.82 (d, 3J (P-
C) ) 10.9 Hz, PAr-Cmeta), 121.93 (Ar-C), 121.66 (3J (Pt-C) )
35.3 Hz, Ar-C), 74.0 (2J (Pt-C) ) 50.3 Hz, CH2N), 65.3 (COH),
50.7 (NCH3). 31P{1H} NMR (CDCl3): δ 20.7 (1J (Pt-P) ) 4261
Hz). Anal. Calcd for C28H29ClNOPPt: C 51.18, H 4.45, N 2.13.
Found: C 51.18, H 4.55, N 2.04.
and distilled prior to use. H and 13C{1H} NMR spectra were
1
recorded at 298 K (unless stated otherwise) on a Varian Inova
300 MHz spectrometer, 31P{1H} NMR spectra were recorded
on a Varian Mercury 200 MHz NMR spectrometer. All NMR
chemical shifts are in ppm referenced to residual solvent
signals (1H and 13C{1H}) or to H3PO4 (31P{1H}). The starting
materials cis-PtCl2(DMSO)2,15 4-[(dimethylamino)methyl]bro-
mobenzene,6 4-[(dimethylamino)methyl]benzaldehyde,16 and
the Fre´chet dendron [G1]-COCl14 were prepared according to
literature procedures. C60 (Hoechst, Gold Grade) was used as
(15) Price, J . H.; Williamson, A. N.; Schramm, R. F.; Wayland, B.
B. Inorg. Chem. 1972, 11, 1280.
(16) Meijer, M. D.; de Wolf, E.; Lutz, M.; Spek, A. L.; van Klink, G.
P. M.; van Koten, G. Organometallics 2001, 20, 4198.

Cycloplatinated Arylamine Ligands
Organometallics, Vol. 21, No. 2, 2002 269
3
3
4
Bis(4-[(d im eth yla m in o)m eth yl]p h en yl)m eth yl Alcoh ol
(4). To a solution of 4-[(dimethylamino)methyl]bromobenzene
(5.80 g, 27.1 mmol) in Et2O (30 mL) at -78 °C was added 37
mL of a 1.5 M solution of t-BuLi in pentane (55 mmol). The
reaction mixture was stirred at -78 °C for 1 h, and a solution
of 4-[(dimethylamino)methyl]benzaldehyde (4.43 g, 27.1 mmol)
in Et2O (25 mL) was added in one portion. The reaction
mixture was allowed to warm to room temperature over 2 h
and was quenched with water (50 mL). The organic layer was
separated, and the water layer extracted with Et2O (2 × 100
mL). The organic fractions were dried on MgSO4, filtered, and
evaporated in vacuo. The crude product was purified using
Kugelrohr distillation giving 4 as a yellow oil, which solidified
H), 7.04 (d, J ) 7.8 Hz, 1H, Ar-H), 6.92 (dd, J ) 7.4 Hz, J
) 1.6 Hz, 1H, Ar-H), 6.80 (t, 4J ) 2.4 Hz, 1H, Ar-H), 6.43
3
4
4
(dd, J (Pt-H) ) 52.8 Hz, J (P-H) ) 3.0 Hz, J ) 1.5 Hz, 2H,
Ar-Hortho), 5.06 (s, 4H, CH2O), 4.62 (s, 2H, CH2O), 4.07 (d,
3J (Pt-H) ) 27.1 Hz, J (P-H) ) 3.0 Hz, 2H, CH2N), 2.99 (d,
3
3J (Pt-H) ) 23.4 Hz, J (P-H) ) 2.8 Hz, 6H, NCH3). 13C{1H}
3
NMR (CDCl3): δ 165.74, 159.60, 147.53 (Ar-C), 137.63 (1J (P-
C) ) 7.1 Hz, PAr-Cipso), 137.48 (2J (Pt-C) ) 86.7 Hz, Ar-C),
136.40, 135.15 (d, 2J (P-C) ) 10.9 Hz, PAr-Cortho), 132.22
(2J (Pt-C) ) 72.3 Hz, Ar-C), 132.11 (Ar-C), 130.54 (PAr-Cpara),
129.77 (4J (Pt-C) ) 31.5 Hz, Ar-C), 128.63, 128.16, 128.03,
3
127.75 (d, J (P-C) ) 10.9 Hz, PAr-Cmeta), 127.58, 123.13 (Ar-
C), 121.57 (4J (Pt-C) ) 32.2 Hz, Ar-C), 108.73, 106.43, 74.1
(2J (Pt-C) ) 51.0 Hz, CH2N), 70.3 (OCH2), 67.0 (OCH2), 50.8
(NCH3). 31P{1H} NMR (CDCl3): δ 20.9 (1J (Pt-P) ) 4235 Hz).
MALDI-TOF (9-NA): m/z 972.82 [M]+, 938.07 [M - Cl]+. Anal.
Calcd for C49H45ClNO4PPt: C 60.46, H 4.66, N 1.44. Found:
C 60.34, H 4.58, N 1.43.
1
upon standing (6.23 g, 77%). H NMR (CDCl3): δ 7.29 (d, 4H,
3J ) 8.4 Hz, Ar-H), 7.20 (d, 4H, 3J ) 8.1 Hz, Ar-H), 5.71 (s,
1H, CHO), 5.08 (s, 1H, OH), 3.34 (s, 4H, CH2N), 2.13 (s, 12H,
NCH3). 13C{1H} NMR (CDCl3): δ 143.5, 137.0, 129.2, 126.4
(Ar-C), 75.4 (COH), 63.8 (CH2N), 45.0 (NCH3). Anal. Calcd for
C
19H26N2O: C 76.47, H 8.78, N 9.39. Found: C 76.29, H 8.90,
N 9.26.
Bis(3-[ch lor o (DMSO) p la t in o]-4-[(d im et h yla m in o)-
1-{4′-[(Dim e t h yla m in o)m e t h yl]b e n zyl}-3-e t h ylm a -
lon a te (8). To a solution of 1 (1.50 g, 9.07 mmol) in CH2Cl2
(40 mL) at -60 °C was added pyridine (0.77 mL, 9.5 mmol). A
solution of ethyl malonyl chloride (1.2 mL, 9.5 mmol) in CH2-
Cl2 (25 mL) was added dropwise, and the solution was allowed
to warm overnight. The solution was washed with a saturated
solution of NaHCO3 (3 × 60 mL), dried on MgSO4, filtered,
and evaporated in vacuo, yielding 8 as a yellow oil (2.03 g,
80%). 1H NMR (CDCl3): δ 7.26 (s, 4H, Ar-H), 5.12 (s, 2H,
OCH2), 4.13 (q, 3J ) 7.5 Hz, 2H, OEt), 3.37 (s, 2H, CH2N),
3.36 (s, 2H, C(O)CH2C(O)), 2.18 (s, 6H, NCH3), 1.19 (t, 3J )
6.9 Hz, 3H, OEt). 13C{1H} NMR (CDCl3): δ 166.2, 166.1 (CO),
139.0, 133.9, 129.0, 128.0 (Ar-C), 66.7 (OCH2), 63.7 (CH2N),
61.2 (OEt), 45.1 (NCH3), 41.3 (C(O)CH2C(O)), 13.8 (OEt). Anal.
Calcd for C15H21NO4: C 64.50, H 7.58, N 5.01. Found: C 64.43,
H 7.51, N 5.05.
m eth yl]p h en yl)m eth yl Alcoh ol (5). Complex 5 was syn-
thesized using the same method as that described for 2
starting from 4 (0.35 g, 1.2 mmol), cis-PtCl2(DMSO)2 (1.01 g,
2.39 mmol), and NaOAc (0.21 g, 2.6 mmol). Complex 5 was
isolated as a white solid (0.91 g, 84%). 1H NMR (CDCl3): δ
8.03 (d, J (Pt-H) ) 48.0 Hz, J ) 1.2 Hz, 2H, Ar-Hortho), 7.13
(dd, 3J ) 7.5 Hz, 4J ) 1.2 Hz, 2H, Ar-H), 6.99 (d, 3J ) 8.1 Hz,
2H, Ar-H), 5.77 (d, 3J ) 3.0 Hz, 1H, CHO), 3.94/3.91 (dd, AB,
2J ) 13.7 Hz, 3J (Pt-H) ) 36.9 Hz, 4H, CH2N), 3.50 (s, 3J (Pt-
3
4
3
H) ) 21.6 Hz, 12H, SCH3), 2.89, 2.88 (2 × s, J (Pt-H) ) 31.5
Hz, 12H, NCH3), 2.29 (d, 3J ) 3.3 Hz, 1H, HOCH). 13C{1H}
NMR (CDCl3): δ 145.0 (4J (Pt-C) ) 18.2 Hz), 142.5, 136.3,
132.5 (2J (Pt-C) ) 55.2 Hz, Ar-C), 123.3 (Ar-C), 121.9 (3J (Pt-
C) ) 37.7 Hz, Ar-C), 77.1 (COH), 74.9 (2J (Pt-C) ) 53.0 Hz,
CH2N), 52.43, 52.38 (NCH3), 47.0 (2J (Pt-C) ) 64.9 Hz, SCH3).
Anal. Calcd for C23H36Cl2N2O3Pt2S2: C 53.79, H 7.05, N 7.84.
Found: C 53.88, H 7.11, N 7.86.
1-[Bis(4-[(d im et h yla m in o)m et h yl]p h en yl)m et h yl]-3-
eth ylm a lon a te (9). To a solution of ethyl malonyl chloride
(0.80 mL, 6.6 mmol) in CH2Cl2 (40 mL) was added a solution
of 4 (0.96 g, 3.2 mmol) in CH2Cl2 (30 mL). The reaction mixture
was stirred for 3 h and evaporated in vacuo. The remaining
white solid was washed with Et2O (4 × 50 mL) and suspended
in CH2Cl2 (50 mL). Then NEt3 (3 mL) was added to the
mixture, upon which the mixture clarified. This was washed
with a saturated NaHCO3 solution (2 × 50 mL) and an aqeous
saturated NaCl solution (50 mL). The organic solution was
dried on MgSO4, filtered, and evaporated in vacuo, yielding 9
Bis(3-[ch lor o(tr ip h en ylp h osp h in e)p la tin o]-4-[(d im eth -
yla m in o)m eth yl]p h en yl)m eth yl Alcoh ol (6). Complex 6
was synthesized using the same method as that described for
3 starting from 5 (0.47 g, 0.51 mmol) and PPh3 (0.27 g, 1.0
mmol), yielding 6 as a white solid (0.52 g, 80%). 1H NMR
(CDCl3): δ 7.75-7.67 (m, 12H, PAr-H), 7.42-7.29 (m, 18H,
3
3
PAr-H), 6.70 (d, J ) 7.5 Hz, 2H, Ar-H), 6.43 (dd, J (Pt-H) )
57.3 Hz, J (P-H) ) 2.9 Hz, J ) 1.3 Hz, 2H, Ar-Hortho), 5.90
4
4
1
as a yellow oil (0.82 g, 62%). H NMR (CDCl3): δ 7.23 (s, 8H,
3
4
3
(dd, J ) 7.7 Hz, J ) 1.3 Hz, 2H, Ar-H), 4.35 (d, J ) 3.6 Hz,
1H, CHO), 4.02/3.98 (dd, AB, 2J ) 13.7 Hz, 4J (P-H) ) 3.0 Hz,
3J (Pt-H) ) 30.5 Hz, 4H, CH2N), 2.97, 2.95 (2 × d, 4J (P-H) )
Ar-H), 6.87 (s, CH), 4.11 (q, 3J ) 6.9 Hz, 2H, OEt), 3.39 (s,
2H, C(O)CH2C(O)), 3.29 (s, 4H, CH2N), 2.15 (s, 12H, NCH3),
1.15 (t, 3J ) 7.2 Hz, 3H, OEt). 13C{1H} NMR (CDCl3): δ 165.9,
165.2 (CO), 138.5, 138.1, 128.7, 126.7 (Ar-C), 77.3 (OCH), 63.6
(CH2N), 61.1 (OEt), 45.0 (NCH3), 41.5 (C(O)CH2C(O)), 13.7
(OEt). Anal. Calcd for C24H32N2O4: C 69.88, H 7.82, N 6.79.
Found: C 70.05, H 7.94, N 6.82.
3
3
2.7 Hz, J (Pt-H) not resolved, 12H, NCH3), 0.52 (d, J ) 3.6
Hz, 1H, OH). 13C{1H} NMR (CDCl3): δ 146.0 (Ar-C), 140.68
(d, 2J (P-C) ) 2.3 Hz, Ar-C), 136.84 (d, 1J (P-C) ) 6.8 Hz, PAr-
C
ipso), 135.18 (d, 2J (P-C) ) 11.0 Hz, PAr-Cortho), 130.89 (Ar-
C), 130.41 (d, 4J (P-C) ) 2.4 Hz, PAr-Cpara), 130.08 (Ar-C),
127.78 (d, 3J (P-C) ) 11.0 Hz, PAr-Cmeta), 121.15 (Ar-C), 120.95
(Ar-C), 76.2 (COH), 74.1 (2J (Pt-C) ) 52.5 Hz, CH2N), 50.9,
50.7 (NCH3). 31P{1H} NMR (CDCl3): δ 21.1 (1J (Pt-P) ) 4281
Hz). Anal. Calcd for C55H54Cl2N2OP2Pt2: C 51.53, H 4.25, N
2.19. Found: C 51.34, H 4.30, N 2.20.
1-{3′-[Ch lor o(tr iph en ylposph in e)platin o]-4′-[(dim eth yl-
a m in o)m eth yl]ben zyl}-3-eth ylm a lon a te (10). To a solution
of 3 (1.26 g, 1.92 mmol) in CH2Cl2 (40 mL) at 0 °C was added
NEt3 (0.40 mL, 2.9 mmol) and ethyl malonyl chloride (0.37
mL, 2.9 mmol). The reaction mixture was stirred for 5 h and
evaporated in vacuo. The remaining white solid was washed
with Et2O (3 × 40 mL) and dissolved in CH2Cl2. The solution
was washed with a saturated solution of NaHCO3 (2 × 40 mL)
and a saturated solution of NaCl (2 × 40 mL), dried on MgSO4,
and evaporated in vacuo, yielding 10 as a white solid (0.80 g,
{3-[Ch lor o(t r ip h en ylp osp h in e)p la t in o]-4-[(d im et h yl-
a m in o)m eth yl]ben zyl}-[G1]-ca r boxyla te (7). To a solution
of 4 (0.67 g, 1.0 mmol) in CH2Cl2 (25 mL) was added NEt3
(0.20 mL, 1.4 mmol). A solution of the Fre´chet dendron [G1]-
C(O)Cl (0.36 g, 1.0 mmol) in CH2Cl2 (25 mL) was added
dropwisely, and the solution was stirred at room temperature
for 3 days. The reaction mixture was washed with an aqeous
saturated NaCl solution (50 mL), dried over MgSO4, filtered,
and evaporated in vacuo. The remaining solid was washed with
Et2O (2 × 15 mL) and dried in vacuo, yielding 7 as a white
solid (0.65 g, 65%). 1H NMR (CDCl3): δ 7.76-7.68 (m, 6H, Ar-
H), 7.46-7.27 (m, 19H, Ar-H), 7.13 (d, 4J ) 2.5 Hz, 2H, Ar-
1
54%). H NMR (CDCl3): δ 7.77-7.67 (m, 6H, PAr-H), 7.43-
7.31 (m, 9H, PAr-H), 7.01 (d, 3J ) 7.5 Hz, 1H, Ar-H), 6.82 (dd,
3J ) 7.5 Hz, 4J ) 1.5 Hz, 1H, Ar-H), 6.35 (dd, 3J (Pt-H) )
4
4
56.7 Hz, J (P-H) ) 2.7 Hz, J ) 1.8 Hz, 1H, Ar-Hortho), 4.48
3
3
(s, 2H, OCH2), 4.17 (q, 2H, J ) 7.3 Hz), 4.05 (d, J (Pt-H) )
28.4 Hz, 3J (P-H) ) 2.8 Hz, 2H, CH2N), 3.12 (s, 2H, C(O)CH2C-
(O)), 2.97 (d, 3J (Pt-H) ) 23.8 Hz, 3J (P-H) ) 2.7 Hz, 6H,
NCH3), 1.22 (t, J ) 6.8 Hz). 13C{1H} NMR (CDCl3): δ 147.66
3

270 Organometallics, Vol. 21, No. 2, 2002
Meijer et al.
(Ar-C), 137.38 (d, 1J (P-C) ) 6.1 Hz, PAr-Cipso), 135.18 (d,
2J (P-C) ) 11.0 Hz, Ar-Cortho), 131.61 (d, 2J (P-C) ) 2.5 Hz,
136.22 (d, 2J (P-C) ) 2.4 Hz, Ar-C), 135.13 (d, 4J (P-C) ) 11.0
1
Hz, PAr-Cortho), 136.64 (d, J (P-C) ) 6.7 Hz, PAr-Cipso), 132.4
4
Ar-C), 130.64 (Ar-C), 130.53 (d, J (P-C) ) 2.4 Hz, PAr-Cpara),
(3J (Pt-C) ) 29.0 Hz, Ar-C), 131.67 (3J (Pt-C) ) 30.4 Hz, Ar-
C), 130.34 (PAr-Cpara), 127.69 (d, 3J (P-C) ) 10.9 Hz, PAr-
3
129.82, 127.81 (d, J (P-C) ) 11.0 Hz, PAr-Cmeta), 122.91 (Ar-
C), 121.56 (Ar-C), 74.0 (2J (Pt-C) ) 56.3 Hz, CH2N), 67.2
(OCH2), 61.4 (OEt), 50.8 (NCH3), 41.3 (C(O)CH2C(O)), 14.0
(OEt). 31P{1H} NMR (CDCl3): δ 21.2 (1J (Pt-P) ) 4236 Hz).
Anal. Calcd for C33H35ClNO4PPt: C 51.40, H 4.57, N 1.82.
Found: C 51.24, H 4.65, N 1.74.
C
meta), 121.85 (Ar-C), 121.14 (Ar-C), 74.1 (2J (Pt-C) ) 46.7 Hz,
CH2N), 61.1 (OEt), 53.3, 52.9 (NCH3), 40.9 (C(O)CH2C(O)), 14.0
(OEt). 31P{1H} NMR (CDCl3): δ 20.0 (1J (Pt-P) ) 4202 Hz).
Anal. Calcd for C60H60I2N2O4P2Pt2: C 45.64, H 3.83, N 1.77.
Found: C 45.88, H 3.76, N 1.85.
1-{Bis(3′-[ch lor o(t r ip h en ylp osp h in e)p la t in o]-4′-[(d i-
m et h yla m in o)m et h yl]p h en yl)m et h yl}-3-et h ylm a lon a t e
(11). Compound 11 was prepared using the same method as
for 10 starting from 6 (2.28 g, 1.78 mmol), ethyl malonyl
chloride (0.34 mL, 2.7 mmol), and NEt3 (0.37 mL, 2.7 mmol),
1,2-Dih ydr o-61-eth oxycar bon yl-61-{4-[(dim eth ylam in o)-
m et h yl]b en zyloxyca r b on yl}-1,2-m et h a n o[60]fu ller en e
(14). To a solution of 8 (0.38 g, 1.3 mmol), C60 (0.91 g, 1.3
mmol), and I2 (0.65 g, 2.5 mmol) in toluene (900 mL) was added
dropwise DBU (1.1 mL, 7.1 mmol). The reaction mixture was
stirred for 17 h and poured on top of a silica gel column.
Elution with toluene afforded 0.20 g of unreacted C60. Elution
with toluene/MeOH (95:5 v/v %) gave the crude product after
evaporation of the solvent. This was dissolved in CS2 (10 mL)
and pentane was added (75 mL), whereupon the product
precipitated. This procedure was repeated and the precipitate
dried in vacuo, yielding 14 as a light brown solid (0.44 g, 35%,
1
yielding 11 as a white solid (1.90 g, 76%). H NMR (CDCl3):
δ 7.71-7.65 (m, 12H, PAr-H), 7.43-7.26 (m, 18H, PAr-H), 6.67
3
(d, J ) 7.5 Hz, 2H, Ar-H), 6.39 (3J (Pt-H) ) 55.2 Hz, 2H, Ar-
3
4
H
ortho), 5.79 (dd, J ) 7.8 Hz, J ) 0.9 Hz, 2H, Ar-H), 5.47 (s,
3
1H, OCH), 4.08 (q, 2H, J ) 6.9 Hz, OEt), 4.01/3.95 (dd, AB,
3J ) 13.5 Hz, 3J (P-H) ) 2.7 Hz, 4H, CH2N), 2.96, 2.93 (2 × d,
3J (P-H) ) 2.7 Hz, 12H, NCH3), 2.46 (s, 2H, C(O)CH2C(O)),
1.15 (t, 3J ) 6.9 Hz, OEt). 13C{1H} NMR (CDCl3): δ 146.47
(Ar-C), 136.64 (d, 1J (P-C) ) 6.7 Hz, PAr-Cipso), 136.47 (d,
1
45% based on reacted C60). H NMR (CS2/C6D6, 3:1 v/v %): δ
3
3
7.23 (d, J ) 8.4 Hz, 2H, Ar-H), 7.21 (d, J ) 8.4 Hz, 2H, Ar-
H), 5.25 (s, 2H, OCH2), 4.21 (q, 3J ) 7.2 Hz, 2H, OEt), 3.27 (s,
2H, CH2N), 2.09 (s, 6H, NCH3), 1.14 (t, 3J ) 7.2 Hz, 3H, OEt).
13C{1H} NMR (CS2/C6D6, 3:1 v/v %): δ 162.73, 162.64 (CO),
144.63, 145.48, 145.46, 145.38, 145.07, 144.96, 144.91, 144.87,
144.82, 144.14, 143.31, 143.25, 142.48, 142.09, 141.19, 141.17,
140.62, 139.56, 139.38, 133.67, 129.24, 129.17 (C60-C and Ar-
C), 71.9 (C60-sp3), 68.6, (OCH2), 64.2 (CH2N), 63.2 (OEt), 52.2
(C(O)CH2C(O)), 45.6 (NCH3), 14.4 (OEt). MALDI-TOF (9-
NA): m/z 997.0 ([M]+). Anal. Calcd for C75H19NO4: C 90.26,
H 1.92, N 1.40. Found: C 90.05, H 1.86, N 1.32.
2J (P-C) ) 2.4 Hz, Ar-C), 135.12 (d, J (P-C) ) 10.9 Hz, PAr-
4
C
ortho), 130.8 (Ar-C), 130.46 (d, 4J (P-C) ) 1.8 Hz, Ar-Cpara),
130.03 (Ar-C), 127.80 (d, 3J (P-C) ) 11.6 Hz, PAr-Cmeta), 121.63
(Ar-C), 121.29 (Ar-C), 77.8 (OCH), 74.1 (2J (Pt-C) ) 49.7 Hz,
CH2N), 61.1 (OEt), 50.9, 50.8 (NCH3), 40.8 (C(O)CH2C(O)), 14.0
(OEt). 31P{1H} NMR (CDCl3): δ 21.6 (1J (Pt-P) ) 4262 Hz).
Anal. Calcd for C60H60Cl2N2O4P2Pt2: C 51.62, H 4.33, N 2.01.
Found: C 51.69, H 4.28, N 1.97.
1-{4′-[(Dim eth yla m in o)m eth yl]-3′-[iod o(tr ip h en ylp os-
p h in e)p la tin o]ben zyl}-3-eth ylm a lon a te (12). To a solution
of 10 (0.44 g, 0.57 mmol) in acetone (25 mL) was added NaI
(0.85 g, 4.4 mmol). The reaction mixture was stirred for 2 h
and evaporated in vacuo. The resultant white solid was
extracted with CH2Cl2 (20 mL). Hexanes (60 mL) were added
to the solution, whereupon a precipitate was formed. This was
isolated and dried in vacuo, giving 12 as a tan solid (0.40 g,
1,2-Dih yd r o-61-et h oxyca r b on yl-61-{b is{4′-[(d im et h -
y la m i n o )m e t h y l]p h e n y l}m e t h y lo x y c a r b o n y l}-1,2-
m eth a n o[60]fu ller en e (15). To a solution of 9 (0.41 g, 0.99
mmol), C60 (0.86 g, 1.2 mmol), and I2 (0.51 g, 2.0 mmol) in
toluene (900 mL) was added DBU (0.90 mL, 7.0 mmol)
dropwise. The reaction mixture was stirred for 17 h and poured
on top of a silica gel column. Elution with toluene afforded
0.23 g of unreacted C60. Elution with toluene/MeOH (95:5 v/v
%) gave the crude product after evaporation of the solvent.
This was dissolved in CS2 (10 mL), and acetone was added
(75 mL), whereupon the product precipitated. This was
isolated, washed with acetone (40 mL), and dried in vacuo,
yielding 15 as a light brown solid (0.53 g, 47%, 54% based on
reacted C60). 1H NMR (CDCl3): δ 7.41 (d, 3J ) 8.1 Hz, 4H,
Ar-H), 7.31 (d, 3J ) 8.1 Hz, 4H, Ar-H), 7.26 (s, 1H, OCH), 4.51
(q, 3J ) 7.5 Hz, 2H, OEt), 3.41 (s, 4H, CH2N), 2.23 (s, 12H,
1
81%). H NMR (CDCl3): δ 7.77-7.69 (m, 6H, PAr-H), 7.44-
7.31 (m, 9H, PAr-H), 7.02 (d, 3J ) 7.5 Hz, 1H, Ar-H), 6.86 (dd,
3J ) 7.8 Hz, 4J ) 1.8 Hz, 1H, Ar-H), 6.35 (dd, 3J (Pt-H) )
4
4
58.2 Hz, J (P-H) ) 3.6 Hz, J ) 1.5 Hz, 1H, Ar-Hortho), 4.48
3
3
(s, 2H, OCH2), 4.17 (q, 2H, J ) 6.9 Hz), 4.09 (d, J (Pt-H) )
3
3
24.0 Hz, J (P-H) ) 2.4 Hz, 2H, CH2N), 3.15 (d, J (Pt-H) )
24.6 Hz, 3J (P-H) ) 3.0 Hz, 6H, NCH3), 3.12 (s, 2H, C(O)CH2C-
(O)), 1.23 (t, 3J ) 6.9 Hz, OEt). 13C{1H} NMR (CDCl3): δ 147.64
(Ar-C), 136.35 (d, 1J (P-C) ) 6.7 Hz, PAr-Cipso), 135.31 (d,
2J (P-C) ) 10.4 Hz, Ar-Cortho), 132.28 (Ar-C), 131.62 (d, 4J (P-
C) ) 2.5 Hz, Ar-C), 130.46 (Ar-C), 130.60 (d, 4J (P-C) ) 3.3
Hz, Ar-Cpara), 127.76 (d, 3J (P-C) ) 11.5 Hz, PAr-Cmeta), 123.14
(Ar-C), 121.80 (3J (Pt-C) ) 32.8 Hz, Ar-C), 74.2 (2J (Pt-C) )
53.4 Hz, CH2N), 67.2 (OCH2), 61.5 (OEt), 53.2 (NCH3), 41.4
(C(O)CH2C(O)), 14.1 (OEt). 31P{1H} NMR (CDCl3): δ 19.7
3
NCH3), 1.14 (t, J ) 7.2 Hz, 3H, OEt). 13C{1H} NMR (CDCl3):
δ 163.51, 162.72 (CO), 145.30, 145.26, 145.20, 145.17, 145.15,
145.03, 144.91, 144.91, 144.88, 144.71, 144.69, 144.67, 144.63,
144.46, 143.89, 143.83, 143.06, 143.01, 142.98, 142.97, 142.22,
142.21, 140.94, 142.21, 141.86, 140.94, 140.90, 139.63, 139.36,
138.51, 137.61, 129.16, 127.62 (C60-C and Ar-C), 79.7 (OCH),
71.5 (C60-sp3), 64.0 (CH2N), 63.5 (OEt), 52.1 (C(O)CH2C(O)),
45.5 (NCH3), 14.2 (OEt). MALDI-TOF (9-NA): m/z 1131.5
([M]+). Anal. Calcd for C84H30N2O4: C 89.19, H 2.67, N 2.48.
Found: C 89.28, H 2.57, N 2.50.
(1J (Pt-P) ) 4189 Hz). Anal. Calcd for C33H35INO4PPt:
45.95, H 4.09, N 1.62. Found: C 45.80, H 3.98, N 1.58.
C
1-{Bis(4′-[(d im et h yla m in o)m et h yl]-3′-[iod o(t r ip h en -
ylposph in e)platin o]ph en yl)m eth yl}-3-eth ylm alon ate (13).
To a solution of 11 (1.43 g, 1.02 mmol) in acetone (50 mL) was
added NaI (1.5 g, 10 mmol). The reaction mixture was stirred
for 2 h and evaporated in vacuo, and the remaining solid was
extracted with CH2Cl2 (50 mL). This was evaporated in vacuo,
1,2-Dih yd r o-61-eth oxyca r bon yl-61-{3′-[ch lor o(DMSO)-
platin o]-4′-[(dim eth ylam in o)m eth yl]ben zyloxycar bon yl}-
1,2-m eth a n o[60]fu ller en e (16). To a solution of 14 (227 mg,
0.227 mmol) in 1,2-dichlorobenzene (50 mL) was added cis-
PtCl2(DMSO)2 (101 mg, 0.239 mmol) and a solution of NaOAc
(20 mg, 0.24 mmol) in MeOH (20 mL). The reaction mixture
was heated at 65 °C for 17 h and evaporated in vacuo. The
crude product was extracted with CS2 (40 mL), filtered, and
evaporated in vacuo. The product was washed with MeOH (2
× 40 mL) and Et2O (2 × 40 mL) and dried in vacuo, yielding
1
yielding 13 as a tan solid (1.38 g, 86%). H NMR (CDCl3): δ
7.72-7.63 (m, 12H, PAr-H), 7.38-7.27 (m, 18H, PAr-H), 6.68
(d, 3J ) 7.8 Hz, 2H, Ar-H), 6.39 (dd, 3J (Pt-H) ) 59.8 Hz, 4J (P-
H) ) 3.5 Hz, 4J ) 1.2 Hz, 2H, Ar-Hortho), 5.70 (dd, 3J ) 7.6 Hz,
3
4J ) 1.2 Hz, 2H, Ar-H), 5.52 (s, 1H, OCH), 4.08 (q, 2H, J )
3
3
7.5 Hz, OEt), 4.05/3.99 (dd, AB, J ) 13.4 Hz, J (P-H) ) 3.0
Hz, 4H, CH2N), 3.15, 3.09 (2 × d, 3J (P-H) ) 2.7 Hz, 12H,
3
1
NCH3), 2.52 (s, 2H, C(O)CH2C(O)), 1.15 (t, J ) 6.9 Hz, OEt).
16 as a brown solid (168 mg, 57%). H NMR (CDCl3): δ 8.10
13C{1H} NMR (CDCl3): δ 166.04, 164.43 (CO), 146.45 (Ar-C),
(d, J (Pt-H) ) 45.9 Hz, J ) 1.2 Hz, 1H, Ar-Hortho), 7.26 (dd,
3
4

Cycloplatinated Arylamine Ligands
Organometallics, Vol. 21, No. 2, 2002 271
4
3
3J ) 7.5 Hz, J ) 1.5 Hz, 1H, Ar-H), 7.09 (d, J ) 7.8 Hz, 1H,
(OEt). 31P{1H} NMR (CDCl3): δ 17.5 (1J (Pt-P) ) 4174 Hz).
MALDI-TOF (9-NA): m/z 2170.1 ([M - I]+). Anal. Calcd for
Ar-H), 4.53 (q, 3J ) 7.2 Hz, 2H, OEt), 4.00 (s, 3J (Pt-H) ) 38.1
Hz, 2H, CH2N), 3.55 (s, J (Pt-H) ) 25.6 Hz, 6H, SCH3), 2.94
3
C120H58I2N2O4P2Pt2: C 62.73, H 2.54, N 1.22. Found: C 62.59,
3
3
(s, J (Pt-H) ) 32.4 Hz, 6H, NCH3), 1.43 (t, J ) 6.9 Hz, 3H,
OEt). 13C{1H} NMR (CDCl3): δ 163.51, 163.48 (CO), 146.89,
145.41, 145.28, 145.24, 145.20, 145.17, 145.14, 144.85, 144.68,
144.65, 144.57, 144.43, 143.86, 143.84, 143.05, 143.01, 142.96,
142.93, 142.22, 142.19, 141.91, 141.89, 140.91, 140.79, 139.25,
138.91, 136.44, 135.08 (2J (Pt-C) ) 52.3 Hz), 132.16, 130.53,
127.70, 125.78, 121.69 (3J (Pt-C) ) 36.9 Hz), 74.7 (2J (Pt-C)
) 53.8 Hz, CH2N), 71.6 (C60-sp3), 69.7 (OCH2), 63.4 (OEt), 52.3
(NCH3), 46.8 (2J (Pt-C) ) 60.8 Hz, SCH3), 14.2 (OEt). Anal.
Calcd for C77H24ClNO5PtS: C 70.83, H 1.85, N 1.07. Found:
C 70.76, H 4.64, N 1.14.
H 2.46, N 1.18.
Cr ysta l Str u ctu r e Deter m in a tion s. X-ray intensities
were measured on a Nonius KappaCCD diffractometer with
rotating anode (Mo KR, λ ) 0.71073 Å) at a temperature of
150 K up to a maximal resolution of sin ϑ/λmax ) 0.65 Å-1. The
structures were solved with automated Patterson methods
with the program DIRDIF9717 and refined with the program
SHELXL9718 against F2 of all reflections. Non-hydrogen atoms
were refined freely with anisotropic displacement parameters;
hydrogen atoms were refined as rigid groups. The drawings,
structure calculations, and checking for higher symmetry were
performed with the program PLATON.19
St r u ct u r e 6: crystallized by diffusion of hexanes into a
saturated solution of 6 in CH2Cl2. C55H54Cl2N2OP2Pt2‚CH2Cl2,
fw ) 1366.95, colorless needle, 0.24 × 0.18 × 0.03 mm3,
monoclinic, P21/c (No. 14), a ) 12.9136(2) Å, b ) 29.0033(4)
Å, c ) 18.1500(2) Å, â ) 129.378(1)°, V ) 5254.58(12) Å3, Z )
4, F ) 1.728 g cm-3, 39 643 measured reflections, 11 898 unique
reflections (Rint ) 0.073). Absorption correction based on
multiple measured reflections (µ ) 5.624 mm-1, 0.59-0.99
transmission); 618 refined parameters, 0 restraints. The
hydroxy and hydrogen substituents at C10 were refined with
a disorder model (pseudo-2-fold rotation). R (I > 2σ(I)): R1 )
0.0366, wR2 ) 0.0870. R (all data): R1 ) 0.0476, wR2 )
0.0923. S ) 1.014. Minimal and maximal residual electron
density between -2.14 and 1.75 e/Å3.
Str u ctu r e 10: crystallized by diffusion of Et2O into a
saturated solution of 10 in CH2Cl2. C33H35ClNO4PPt, fw )
771.13, colorless needle, 0.54 × 0.15 × 0.09 mm3, orthorhombic,
Pbcn (No. 60), a )32.2580(2) Å, b ) 9.2442(1) Å, c ) 20.8170-
(1) Å, V ) 6207.62(8) Å3, Z ) 8, F ) 1.650 g cm-3, 93 074
measured reflections, 7101 unique reflections (Rint ) 0.068).
Analytical absorption correction (µ ) 4.696 mm-1, 0.13-0.70
transmission); 373 refined parameters, 0 restraints. R (I > 2σ-
(I)): R1 ) 0.0222, wR2 ) 0.0533. R (all data): R1 ) 0.0271,
wR2 ) 0.0553. S ) 1.046. Minimal and maximal residual
electron density between -0.89 and 1.11 e/Å3.
Str u ctu r e 13: crystallized by diffusion of Et2O into a
saturated solution of 13 in CH2Cl2. C60H60I2N2O4P2Pt2, fw )
1579.02, yellow needle, 0.18 × 0.06 × 0.03 mm3, monoclinic,
C2/c (No. 15), a ) 30.3152(5) Å, b ) 11.1579(2) Å, c ) 18.7133-
(3) Å, â ) 116.5565(7)°, V ) 5662.01(17) Å3, Z ) 4, F ) 1.852
g cm-3, 42 384 measured reflections, 6461 unique reflections
(Rint ) 0.070). Analytical absorption correction (µ ) 6.130
mm-1, 0.59-0.85 transmission); 359 refined parameters, 3
restraints. The molecule has an exact, crystallographic C2
symmetry, leading to rotational disorder at carbon C10. R (I
> 2σ(I)): R1 ) 0.0269, wR2 ) 0.0524. R (all data): R1 )
0.0374, wR2 ) 0.0554. S ) 1.042. Minimal and maximal
residual electron density between -0.83 and 1.47 e/Å3.
1,2-Dih yd r o-61-eth oxyca r bon yl-61-{4′-[(d im eth yla m i-
n o)m et h yl]-3′-[iod o(t r ip h en ylp osp h in e)p la t in o]b en zyl-
oxyca r bon yl}-1,2-m eth a n o[60]fu ller en e (17). To a solution
of 14 (173 mg, 0.200 mmol), C60 (208 mg, 0.288 mmol), and I2
(100 mg, 0.388 mmol) in toluene (200 mL) was added DBU
(0.12 mL, 0.80 mmol) dropwise. The reaction mixture was
stirred for 17 h and poured on top of a silica gel column. A
purple-colored fraction was eluted with toluene, affording 0.12
g of unreacted C60. Elution with toluene/MeOH (95:5 v/v %,
red-colored fraction) gave the crude product after evaporation
of the solvent. This was washed with acetone (40 mL) and
dried in vacuo, yielding 17 as a light brown solid (118 mg, 37%,
60% based on reacted C60). 1H NMR (CDCl3): δ 7.78-7.72 (m,
3
6H, PAr-H), 7.42-7.33 (m, 9H, PAr-H), 7.08 (d, J ) 7.7 Hz,
3
3
1H, Ar-H), 7.04 (d, J ) 8.2 Hz, 1H, Ar-H), 6.40 (d, J (Pt-H)
) 55.3 Hz, 4J (P-H) ) 3.3 Hz, 1H, Ar-Hortho), 4.78 (s, 2H,
OCH2), 4.44 (q, 2H, 3J ) 7.1 Hz), 4.12 (d, 3J (Pt-H) ) 26.1 Hz,
3J (P-H) ) 2.7 Hz, 2H, CH2N), 3.17 (d, J (Pt-H) ) 24.6 Hz,
3
3J (P-H) ) 2.7 Hz, 6H, NCH3), 1.31 (t, J ) 7.6 Hz, OEt). 13C-
3
{1H} NMR (CDCl3): δ 163.36, 163.26 (CO), 148.08, 145.28,
145.26, 145.23, 145.20, 145.14, 145.13, 144.90, 144.71, 144.69,
144.62, 144.58, 144.55, 143.89, 143.10, 143.06, 143.04, 143.00,
142.24, 20, 141.93, 141.81, 140.98, 140.89, 139.06, 135.32 (d,
4J (P-C) ) 10.4 Hz, PAr-Cortho), 132.18, 130.62 (PAr-Cpara),
128.02, 127.84 (d, 3J (P-C) ) 11.0 Hz, PAr-Cmeta), 123.71,
121.97, 74.2 (CH2N), 71.6 (C60-sp3), 69.0 (OCH2), 63.3 (OEt),
53.2 (NCH3), 14.1 (OEt). 31P{1H} NMR (CDCl3): δ 20.1 (1J (Pt-
P) ) 4167 Hz). MALDI-TOF (9-NA): m/z 1454.0 ([M - I]+).
Anal. Calcd for C93H33INO4PPt: C 70.64, H 2.10, N 0.89.
Found: C 70.46, H 2.11, N 0.86.
1,2-Dih yd r o-61-eth oxyca r bon yl-61-{bis{4′-[(d im eth yl-
a m in o)m e t h yl]-3′-[iod o(t r ip h e n ylp osp h in e )p la t in o]}-
m eth yloxyca r bon yl}-1,2-m eth a n o[60]fu ller en e (18). To a
solution of 15 (346 mg, 0.219 mmol), C60 (205 mg, 0.285 mmol),
and I2 (100 mg, 0.388 mmol) in toluene (200 mL) was added
DBU (0.12 mL, 0.80 mmol) dropwise. The reaction mixture
was stirred for 17 h and poured on top of a silica gel column.
A purple-colored fraction was eluted with toluene, affording
116 mg of unreacted C60. Elution with toluene/MeOH (95:5 v/v
%, red-colored fraction) gave the crude product after evapora-
tion of the solvent. This was washed with hexanes (40 mL)
and dried in vacuo, yielding 18 as a light brown solid (168 mg,
33%, 59% based on reacted C60). 1H NMR (CDCl3): δ 7.64-
Ack n ow led gm en t. This work was supported by the
Council for Chemical Sciences of The Netherlands
Organization for Scientific Research (CW-NWO).
3
7.57 (m, 12H, PAr-H), 7.26-7.23 (m, 18H, PAr-H), 6.77 (d, J
3
) 7.2 Hz, 2H, Ar-H), 6.34 (d, J ) 7.2 Hz, 2H, Ar-H), 6.39 (s,
Su p p or t in g In for m a t ion Ava ila b le: Tables of X-ray
data for complexes 6, 10, and 13. This material is available
free of charge via the Internet at http://pubs.acs.org.
2H, Ar-Hortho), 5.97 (s, 1H, OCH), 4.36 (q, 2H, 3J ) 7.2 Hz,
OEt), 4.25/3.90 (AB, J (AB) ) 13.8 Hz, 4H, CH2N), 3.27, 3.97
3
3
(2 × d, J (P-H) ) 2.7 Hz, 12H, NCH3), 1.23 (t, J ) 6.9 Hz,
OEt). 13C{1H} NMR (CDCl3): δ 163.27, 161.88 (CO), 147.04,
145.35, 145.24, 145.15, 145.11, 144.98, 144.84, 144.75, 144.64,
144.58, 144.55, 144.39, 144.34, 143.86, 143.80, 143.10, 143.09,
143.05, 142.96, 142.91, 142.21, 142.13, 141.88, 144.66, 140.92,
140.69, 139.42, 138.62, 135.95 (d, 1J (P-C) ) 6.2 Hz, PAr-Cipso),
OM010500G
(17) Beurskens, P. T.; Admiraal, G.; Beurskens, G.; Bosman, W. P.;
Garcia-Granda, S.; Gould, R. O.; Smits, J . M. M.; Smykalla, C. The
DIRDIF97 program system, Technical Report of the Crystallography
Laboratory; University of Nijmegen: The Netherlands, 1997.
(18) Sheldrick, G. M. SHELXL-97, Program for crystal structure
refinement; University of Go¨ttingen, Germany, 1997.
134.96 (d, J (P-C) ) 10.4 Hz, PAr-Cortho), 134.62 (2J (P-C) )
4
2.0 Hz, Ar-C), 132.37, 131.54, 130.36 (PAr-Cpara), 127.75 (d,
3J (P-C) ) 11.2 Hz, PAr-Cmeta), 123.34, 121.64, 80.4 (OCH),
74.3 (CH2N), 71.5 (C60-sp3), 63.1 (OEt), 54.3, 51.9 (NCH3), 14.1
(19) Spek, A. L. PLATON. A multipurpose crystallographic tool;
Utrecht University: The Netherlands, 2000.